Is it possible that health effects may not occur until more than 72 hours after exposure to ricin?
The information that exists on ricin poisoning in humans is extremely limited. Much of what we know about ricin poisoning comes from animal studies and only a few human cases. Nevertheless, enough information exists on ricin poisoning by ingestion (swallowing) to say that it is extremely unlikely that the onset of signs and symptoms of ricin poisoning by ingestion would occur more than 10 hours after exposure. Much less information exists on ricin poisoning by inhalation (breathing in ricin), but initial poisoning symptoms are very unlikely to begin more than 24 hours after exposure.
